1. Field Of The Invention
The invention relates to a process for recovering the enamel slimes in electro-immersion enameling plants with a basin for electrophoretic immersion enameling (EIE-basin) and with at least one rinsing basin located in the down-stream direction of the process.
2. The Prior Art
In electrophoretic immersion enameling, which is referred to by the abbreviation "EIE", about one third of the enamel slimes used are, as a rule, charged in the rinsing basin, which follows the EIE-basin in the process sequence. Primarily for cost reasons, this rinsed off enamel has to be recovered and returned into the process. Processes for the recovery of the enamel slimes are known from DE-Al-34 33 576 and DE-Al-31 21 604. For these purposes, DE-Al-34 33 576 describes a process and device for the recovery of the enamel slimes in which the coated part, upon leaving the EIE-basin, is directly transported into a rinsing basin downstream. The rinsing basin is equipped with an agitator which moves the rinsing water into forced flow, such that a portion of the rinsing water is sent into a settling zone with a reduced flow rate, whereupon the settling enamel is transported back into the EIE-basin.
The drawback of the known process and device lies basically in the fact that the slimes resulting from the recovered enamel have properties different from those of the slimes present in the coating basin. In particular the conductivity, pH, density and the content of auxiliary substances, among others, are different, with the consequence that a compensation is required in order to be able to reuse the recovered slimes. In this connection, one problem is that the ratio between the electrically deposited quantity of enamel and the quantity of enamel brought into the rinsing bath is not always constant. This lack of constancy is caused, for example, by the fact that parts in the bath have highly varying drawing capacities.